1. Technical Field
The present invention relates to an ink composition for marking on a release-treated surface. More particularly, the present invention relates to an ink composition for marking on a release-treated surface, comprising a binder resin with a glycidyl group introduced as a functional group thereinto.
2. Description of the Related Art
Protective films are widely used to protect base films from mechanical damage or contamination during production, storage, and distribution.
For release-treated, a protective film is usually coated with a silicon-based material that is low in surface energy. The release-treated aims to prevent the contamination of the protective film with external contamination sources as well as to readily release the protective film.
Due to its low surface energy, however, the release-treated film is difficult to coat with other materials. This is intended by the design of release-treated, but has the disadvantage that it is difficult to print or mark on the release-treated film. That is, a film with low surface energy does not permit ink to be printed or marked thereon because of its water or oil repellency. If printed on the film, ink is highly apt to be released, which may produce secondary contamination on a substance in contact with the surface of the film.
To solve this problem, Japanese Unexamined Patent Application Publication No. 1995-026188 discloses an ink composition comprising a water-soluble binder resin containing a glycidyl group, water, and a water-miscible solvent. To be dissolved in a water-miscible solvent, however, the binder should be given a specific acid value. In addition, it takes more time to dry a water-miscible solvent than an organic solvent.
There is therefore a need for an ink composition for marking on a release-treated surface that can overcome the problems encountered in the art.